Conventionally, there is proposed an illuminating system including a plurality of luminaires, a plurality of sensor parts and an operation unit (for example, refer to JP 2013-33652 A (hereinafter referred to as “Document 1”)).
Each of the plurality of luminaires in the illuminating system described in Document 1 includes a light source, a housing, a lighting circuit, a controller and a radio part. The housing is formed of metal.
The housing is provided inside thereof with an antenna configuring the radio part. Innumerous through holes are provided in the housing. The antenna is arranged at a position where it can be viewed from any of the through holes.
It is described in Document 1 that the antenna is arranged at the position where it can be viewed from any of the through holes and accordingly signals for wireless communication (for receiving) to the antenna can avoid being shielded by the housing.
There is a demand for miniaturizing this type of luminaire. However, if a miniaturization of each of the plurality of luminaires in the illuminating system described in Document 1 is considered, it may be difficult to arrange the antenna in a vicinity of any of the through holes, which may possibly cause deterioration in communication performance.